The present invention relates to a dialysis machine for the purification of blood, a manifold for the dialysis machine as well as to a process for the regeneration of the dialysis bath.
Dialysis works on the principles of the diffusion of solutes and ultrafiltration of fluid across a semi-permeable membrane. Blood flows by one side of a semi-permeable membrane, and a dialysate or fluid flows by the opposite side. Smaller solutes and fluid pass through the membrane. The blood flows in one direction and the dialysate flows in the opposite. The counter-current flow of the blood and dialysate maximizes the concentration gradient of solutes between the blood and dialysate, which helps to remove more urea and creatinine from the blood. The concentrations of solutes (for example potassium, phosphorus, and urea) are undesirably high in the blood, but low or absent in the dialysis solution and constant replacement of the dialysate ensures that the concentration of undesired solutes is kept low on this side of the membrane. The dialysis solution has levels of minerals like potassium and calcium that are similar to their natural concentration in healthy blood. For another solute, bicarbonate, dialysis solution level is set at a slightly higher level than in normal blood, to encourage diffusion of bicarbonate into the blood, to act as a pH buffer to neutralise the metabolic acidosis that is often present in these patients. The levels of the components of dialysate are typically prescribed by a nephrologist according to the needs of the individual patient.
A dialysis machine is known from US 2006/0173395, U.S. Pat. Nos. 4,213,859 A and 4,137,168A.
Document US 2006/0173395 A1 discloses a combined arterial and venous blood tubing set for transport of blood between a patient and a blood processing unit. The set comprises an arterial set component comprising arterial tubing having an arterial patient connector at one end and an arterial unit connector at the other. A venous set component has venous tubing with a venous patient connector at one end and a venous unit connector at the other end. The arterial and venous patient connectors, and the arterial and venous unit connectors, are respectively, substantially, and releasably directly connected to each other. As a result of this, the arterial, and venous set components cooperate to form a loop.
An apparatus for the infusion of medicaments and drugs, in particular heparin, into the partial vacuum region of an extracorporeal blood circuit is described in U.S. Pat. No. 5,015,226 which replaces a heparin pump and which comprises a supply container in the form of a syringe, a shutoff member, which may be a clamp, disposed in the feed conduit, a means for measuring the reduced pressure or partial vacuum in the extracorporeal circuit and a control means. Said control means is connected to the pressure measuring means and the shutoff member and constructed for periodic opening and closing of the shutoff member in dependence upon the measured partial vacuum and the desired amount of medicament. The apparatus may be used in the extracorporeal blood circuit of a dialysis apparatus.
A fluid manifold which includes a housing having a first inlet and an outlet and a plurality of inlets intermediate the first inlet and the outlet is known from U.S. Pat. No. 5,431,185. Document EP 0 443 324 A1 discloses a system for preparation of a fluid intended for medical use.
A dialysis machine is a machine that filters a patient's blood to remove excess water and waste products when the kidneys are damaged, dysfunctional, or missing. Blood is drawn through a specially created vein in the forearm, which is called an arterio-venous (AV) fistula. From the AV fistula, blood is taken to the dialysis machine through flexible tube. The dialysis machine itself can be thought of as an artificial kidney. Inside, it consists of more flexible tube that carries the removed blood to the dialyzer, a bundle of hollow fibers that forms a semipermeable membrane for filtering out impurities. In the dialyzer, blood is diffused with a saline solution called dialysate, and the dialysate is in turn diffused with blood. Once the filtration process is complete, the cleansed blood is returned to the corresponding vein of the patient. Most patients using dialysis due to kidney impairment or failure use a dialysis machine at a special dialysis clinic. Most sessions take about four hours, and typically patients visit the clinic three times per week.
In order to prevent clotting in the course of a dialysis procedure, it is necessary to deliver continuously a pharmaceutical like Heparin into one of the tubes and thus into the blood circulation. Towards the end of a dialysis procedure, it is necessary or at least helpful to administer medicaments like iron sucrose for example Venofer®, erythropoietin (EPO) and the active form of vitamin D in addition to heparin. At the end of a dialysis session, it is helpful to deliver a medicament in order to wash the outlet of the fistula. At least some of the medicaments cannot be administered within a short period. Instead of that, it is necessary to input such a medicament stepwise or continuously into a tube of the dialysis machine during a period of several minutes like ten minutes.
For the delivery of pharmaceuticals during a dialysis procedure, the tube of a dialysis machine comprises one or more injection sites as known from U.S. Pat. No. 6,090,066. An injection site may be an elastic, needle-pierceable membrane and/or a female luer lock connector for connecting an administration device like a syringe or an adapter for a vial with the injection site.
A staff member of a clinic has to take care of several patients at the same time. At the beginning, a staff member has to connect every patient to a dialysis machine. After a few hours at the end of these procedures, the staff member has to input the medicaments to the corresponding tubes of the dialysis machines. Due to the time pressure, it is difficult to administer all medicaments to all patients every day without making any mistake.